Acta Societatis pro Flora et Fauna Fennica, 48, N:o 7. 65 



dispositis, inter eas in area media plane glabra [N:o 880]; 

 /?) bidentula, forma membrana densissime poris subtilissimis 

 sparsis ornata, medio plane glabra. Long. 19,5 — 20,?, lat. 

 max. 20,- — 21,8, lat. min. 17,2 //. Forma altera poris minus 

 dense in series transversales 5 + 5. Long. 14 — 16, 17 — 19, 

 lat. max. 18, 19,8, lat. min. 15,8, 14,5 //. Cfr. etiam var. 

 tatrica Racib., Desm. Polon. pi. 14 f. 5. [N:o 851, 896]. 



Hab. All forms in Gov. Archangel. — PI. 6 fig. 9. 



This species appears to be composed of numerous forms 

 of various size and outline. The different varieties, which 

 are founded upon the outline of the cells, as f. typica, var. 

 hians and v. tatrica, all include „formae circulares, bidentulae, 

 tridentulae" . Therefore I do not think it possible to separate 

 these „forms" as systematical varieties, but merely as ana- 

 logous forms of the 2 — 3 — 4 — 5— 6-radiate Staurastra. 



Genus Desmidium Ag. 



D. baileyi (Ralfs) De Bary var. coelatum (Kirchn.) 

 Nordst., N.-Zeal. p. 27 pi. 2 f. 6—7. A vertice visum 

 quadrangulum marginibus levissime sed conspicue retusis, 

 angulis rotundatis, processubus connexis angustissime cuneatis- 

 rimaeformibus. Long. (incl. proc.) 16, lat. max. 21 — 23, lat. 

 min. (apex) 19//, [N:o 960b]. Cfr. Turner, E.-Ind. 



pag. 148. 



Hab. Messuby (W). — PI. 5 fig. 27. 



Genus Gymnozyga Ehr. 



G. confervacea West, N.-Amer. pi. 12 f. 20—21 ; G r 6 n- 

 blad, Desm. Keur. pi. 4 f. 31. Long. 20—25—27, lat. max. 

 11,5—12,6—11,5, lat. min. (apex) 10—10,6—10,2//. [N:o 838, 

 1214]. 



Hab. Keuru (C); Gov. of Archangel. PI. 6 fig. 2—4. 



